Arabic (عقد الإشتراك) for a contract (aqd) that entails sharing in ventures/ businesses and profits (ribh) through specific partnership (sharakah/sharikah). Aqd al-ishtirak comes in various forms including mudarabah (aqd al-mudarabah), musaqat/musaqah (aqd al-musaqat/aqd al-musaqah), mugharasah (aqd al-mugharasah), muzara’ah, (aqd al-muzara’ah), etc.

For example, in mudarabah two parties enter into an agreement whereby one (rab al-mal) provides an amount of money (or generally any type of capital), while the other  (mudarib) contributes labor, i.e., efforts to invest the capital. The positive outcomes (profits) are shared by the two parties according to a specific ratio (pre-agreed percentage), while the negative outcomes (losses) are borne by the provider of funds (rab al-mal) unless such losses are caused by mudarib due to negligence (ihmal) or misconduct/mismanagement (taqseer).